Outboard motors generally include a water pump to pump water from the lower portion of the shaft housing, through the water jacket surrounding the cylinder and out the water discharge. When the water pump in an outboard motor fails, continued operation of the motor results in overheating and possible damage to the motor. Thus, failure of the water pump can mean that the boat on which it is used is stranded.
Efforts have been made to provide an auxiliary water cooling system for an outboard motor to avoid the use of the motor without cooling. One example of an auxiliary water cooling system, as shown in U.S. Pat. No. 3,240,181 involves the use of a forward facing scoop connected by a tube 42 to a plate secured over the water inlet in the lower portion of the shaft housing. Installation of this device involves the attachment of the plate to the lower portion of the shaft housing by screws which is difficult in the water. Also, this hose structure must support the scoop and a U-bend in a position immediately behind the propeller with only its connection to the plate and a single support strut connecting to the hose ahead of the U-bend and the scoop. Such structure is expensive because it requires heavy construction or be subject to failure due to the extremely high loading resulting from the movement of the scoop through the water. Also, it does not by-pass the water pump and the water passages in the shaft housing. Similar scoops permanently installed have been used as a water cooling system for inboard motors as evidenced by U.S. Pat. No. 1,099,684.